1. Field of the Invention
This invention relates to aerosol spray dispersal and more specifically to the dispersal of static electricity developed on a spray nozzle during discharge of aerosol spray-type products.
2. Related Art
Many industrial processes give rise to electrostatic charges that develop on work stations and workpiece materials. Electrostatic charges are typically generated by friction between moving parts or materials, and are discharged when a charged object or material comes into contact with another object or material having a different charge. Static electricity can also be discharged through the human body should a worker make simultaneous contact between two objects of differing charges. Electrostatic charges of ordinary scale, e.g., those developed by walking across a carpeted room, do not normally pose a safety problem to humans or to a wide variety of industrial tools or products. However, static electricity is considered to be a significant hazard in relation to the production of modern electronic components, especially those incorporating integrated circuitry. Such circuitry is often very delicate and can be irretrievably damaged by the current created when otherwise innocuous quantities of static electricity are discharged through a workpiece comprising the circuit. The threat becomes more acute as integrated circuitry becomes increasingly miniaturized.
A variety of aerosol products are useful in the assembly of electronic components, e.g., soldering flux remover, circuitry coolant, cleaners, protective coatings, lubricants, release agents, and dusters. However, as these products flow through the aerosol dispenser valve upon use, they develop electrostatic charges to a degree that poses a hazard to the components on which they are used. One product that is available to alleviate this hazard comprises an aerosol dispensing spout .that includes a grounding wire that attaches to the spout, to the workpiece and/or to a ground to which the user is also grounded. The device is described as insulating the user from the static electricity. The device is sold under the trade designation AEROGROUND.TM. and is sold by the Tech Spray Company of Amarillo, Texas. The AEROGROUND.TM. device is believed to be described in U.S. Pat. No. 4,819,837, dated Apr. 11, 1989, to Goforth.
A known expedient for preventing the discharge, onto a workpiece, of static electricity carried by a worker is to ground the worker by attaching a ground wire to his or her body. One such device is a wrist strap such as may be obtained from Charleswater Products, of West Newton, Mass.